Composite material having cementitious properties

ABSTRACT

A composite material, useful as a surgical, medical or orthopedic wrapping, is provided which will adhere or cohere to another surface or to itself by the application of moderate pressure either at room temperature or at an elevated temperature and will be substantially non-tacky to the touch until the application of such moderate pressure. The composite material comprises a cementitious core having bonded thereto a flexible, open cellular, resilient polymeric protective covering, the core having sufficient softness at the conditions of use to extend through the cells of the protective covering and become available at the outer surface thereof upon application of moderate pressure.

0 United States Patent 1 1 1111 3,763,858

Buese Oct. 9, 1973 i [54] COMPOSITE MATERIAL HAVING 3,553,051 l/1971Warrack et a]. 161/190 CEMENTITIOUS PROPERTIES 2,740,402 4/1956 Scholl2,750,314 6/1956 Bemmels e tor: George J. Buese, East Brunsw1c 2,364,00111/1944 Schieman 161/167 v NJ. FOREIGN PATENTS OR APPLICATIONS 1731Assigneei Jllhlm" Johns, New 840,210 7/1960 Great Britain 161/190Brunswick, NJ.

{22] Filed; 24, 1971 Primary Examiner-Alfred L. Leavitt AssistantExaminer-C. B. Cosby [21 1 Appl- N05 118,462 Attorney-Jason Lipow,Harold L. Warner and Robert Related us. Application Data [63]Continuation-in-part of Ser. No. 39,816, May 22,

1970, abandoned. [57] ABSTRACT A composite material, useful as asurgical, medical or 52 us. or 128/156, 117/122, 128/90, Orthopedic pp gis provided which will adhere or 123/155 128/15 161/l60 1 1/1 7 cohereto another surface or to itself by the applica- 161 90 247 55 260/783tion of moderate pressure either at room temperature 511 161. CI A61115/00, B32b 27/40 or at an elevated temperature and will besubstantially 58 P161061 Search l6l/l90, 159, 161, non-tacky to the muchuntil the application of such 161/16() 167; 156/78 79; 117/122; 128/155moderate pressure. The composite material comprises 15 90 a cementitiouscore having bonded thereto a flexible, open cellular, resilientpolymeric protective covering, 5 References Cited the core havingsufficient softness at the conditions of UNITED STATES PATENTS use toextend through the cells of the protective covering and become availableat the outer surface 2 283 242 55132 gzgfj ei ef a i 61/190 x thereofupon application of moderate pressure. 3:425:890 2/l969 Powers 161/19010 Claims, 7 Drawing Figures COMPOSITE MATERIAL HAVING CEMENTITIOUSPROPERTIES CROSS REFERENCE TO RELATED APPLICATION This is acontinuation-in-part of my copending appli cation Ser. No. 39,816, filedMay 22, 1970 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to a composite material, non-tacky to the touch, whichwill adhere to a surface or cohere to itself upon the application ofmoderate pressure either with or without prior heating. Morespecifically, in certain embodiments it relates to wrappings in thenature of adhesive or cohesive bandages, tapes, closures or the like formedical, surgical or orthopedic uses which are highly breathable,convenient to use, comfortable to wear and inexpensive to produce.

While the present invention will be described in connection with'particular embodiments designed for application in the medical, surgicaland orthopedic field, it should be understood that the use of theinvention is not necessarily limited thereto. It can be employed forvarious other home, commercial and industrial applications such as, forexample, as a construction material in the arts and crafts field. Otherapplications willbecome apparent to those skilled in the art from thedescription herein.

2. Description of the Prior Art Wrappings are employed in the medical,surgical, and orthopedic field for a number of purposes such as, forexample, holding surgical pads, bandages and the like in place or forimmobilizing parts of the body as with orthopedic bandages, splints andcasts. In each of these uses, it is desirable to have a wrapping whichcan conveniently be applied and conformed to a part of the body andwhich will remain in place after application and be comfortably worn. lnthe case of certain orthopedic uses, the wrapping should also be capableof setting into a rigid, immobilizing, supporting cast or splint.

Drawbacks have been encountered in using prior wrapping materials. Forexample, an overwrap bandage made of a flexible material, designed toconform to an irregularly shaped member of the body, and held in placewith adhesive tape, has been used to hold surgical dressings in place.The tacky surface of the adhesive tape presents handling and unwinddifficulties and collects lint, dust and dirt, thereby decreasingadhesion and presenting antiseptic problems. Because of the quick grab"characteristic of the exposed tacky surface, it is difficult to adjustand reposition the tape as it is applied. While some attempts have beenmade to protect the tacky surface of adhesive tape by providinginterliners, these have greatly increased the cost of the tape,necessitated an extra application step in that the interlining mustfirst be removed and, additionally, the user is still presented with atacky surface.

A similar problem exists in the case of certain orthopedic cast andsplint forming wrappings which comprise a flexible carrier impregnatedwith a settable material. In my copending patent application, Ser. No.92,096, filed Nov. 23, 1970 now abandoned, I disclose an orthopedicwrapping comprising a foam carrier impregnated therethrough with athermoplastic polymeric material which is softened and rendered cohesiveby heating to an elevated temperature. The heated, impregnated foam isthen wrapped in layers around a body member and, by applying moderatepressure, the layers are cohered to one another. Upon cooling, a smooth,rigid cast is formed. It has been found that, when heated, thethermoplastic material exhibits the quick grab properties and theproblems associated therewith as described above in connection with thesurgical wrappings. Further, certain of the suitable thermoplasticmaterials disclosed in my abovereferenced copending application becometacky when heated and thereby cause inconveniences during application.

SUMMARY OF THE INVENTION In accordance with this invention, a compositematerial is provided which will adhere to another surface or to itselfby the application of at least moderate pressure and which issubstantially non-tacky to the touch until the application of suchpressure. The term moderate pressure is meant to denote the pressurewhich may be conveniently applied by hand or with the aid of a simplehandheld instrument such as a spatula or the like. The compositematerial comprises a cementitious core having at least one flexible,open cellular, protective covering. The term cementitous is meant toencompass the adhesive or cohesive property of a material, exhibitedeither at room temperature or at an elevated temperature of use. Thecementitious core has sufficient softness either at room temperature orat an elevated temperature of use to extend through the cells of theprotective covering and become available for adhesion or cohesion at theouter surface of the protective covering uppon application of moderatepressure. On the other hand, the softness is insufficient to render theproduct inconveniently tacky and/or cohesive or adhesive until pressureis applied and so the product may be stored or heated in roll form andwill exhibit no great unwind difficulties. The product may be applied toa member of the body and readjusted several times without exhibiting theaforementioned quick grab" property, and after the product has beensatisfactorily positioned, the user simply applies moderate pressure tocompress the covering and make the cementitious core available foradhesion or cohesion at the exposed surface thereof. In a preferredembodiment the protective covering comprises two outer layers, at leastone of which is compressible polyurethane foam.

In a specific embodiment of this invention, the core comprises athermoplastic material which may be rendered cementitious and soft byheating to an elevated temperature. The composite material is in theform of an orthopedic wrap which can be wound into a roll for storage,heated in the roll form, applied to a body member, compressed to gaincohesion, and thereafter cooled to form a rigid cast or splint. In thisparticular use, the protective covering, in addition to obviating theproblems associated with the tackiness and quick grab of the heated coremass, serves the added function of heat insulating the product, bothfrom the point of view of protecting the user from discomfort inhandling the product at an elevated temperature as well as preventingthe core from too rapidly cooling and prematurely setting before thewrap can be properly applied.

The invention contemplates providing a protective covering of foamalternatively on one or both sides of a cementitious core, the choice ofsuch alternative being determined primarily by the nature of the coreand the ultimate use of the product. For example, when an essentiallycohesive, non-adhesive, non-tacky core is used as a splint formingmaterial, one layer of foam is sufficient to avoid unwind and quick grabproblems, the non-tacky surface causing no inconvenience duringapplication which would necessitate a second foam layer. On the otherhand, where a tacky, adhesive core mass is used, to avoid theinconvenience in handling such a product, it is advantageous to employtwo foam layers. Further, where the product must be used at atemperature which would discomfort either the applier or the wearer, itis advantageous to provide two layers of foam as heat insulation.

THE PROTECTIVE COVERING The flexible, compressible, open cellularprotective covering used in one or both outer layers is preferablypolyurethane and may be either polyester or polyether polyurethane foam,typically having a density of about 1 to 6 pounds per cubic foot.Polyester polyurethane foams are preferred in the practice of thepresent invention because cell size may be more readily controlled andbecause of their superior tensile strength characteristics. A typicalpolyester polyurethane foam may be prepared, for example, as set forthin Example ll of U. S. Pat. No. 2,956,310.

Generally, a suitable foam should have a degree of openness sufficientto provide exposure of the core therethrough upon the application ofmoderate pressure when the product is at the temperature of use. On theother hand, the degree of openness must be small enough to precludesubstantial premature exposure of the core through the foam which couldrender the product inconveniently tacky, interfere with the unwindproperties, or otherwise impede the use of the product.

While a variety of foam configurations can satisfy the degree ofopenness requirements of this invention, it is preferred to usereticulated foams, i.e., those foams wherein the cell walls have beenremoved by chemical or mechanical treatment. A good measure of thedegree of openness in such foams is the pore density or the number ofcells per running inch (hereinafter "ppi"). l have found that the degreeof openness criteria are best met by reticulated foams having a poredensity of from about 20 to about 120 ppi and preferably from about 20to I ppi. A limiting factor on pore density arises in that it isdifficult, on a production basis, to slice foams having less than aboutppi below a thickness of one-eighth inch. As set forth hereinafter, foamlayer thicknesses of less than one-eighth inch are preferred for manyapplications. Still another factor limiting use of the larger pore sizefoams is that they are harsher to the feel than finer pore sizes.

It should be clearly understood that while reticulated foams having theabove-prescribed pore densities are preferred, other foam configurationssatisfying the degree of openness criteria may be used such as, forexample, sufficiently porous non-reticulated or partially reticulatedfoams, perforated foams and foams having combinations of theseconfiguration characteristics. Because of the cell walls present innon-reticulated or partially reticulated foams, the preferred pore sizeshould be somewhat larger than in the case of fully reticulated foams inorder to obtain a sufficient degree of openness. For example, in aparticular embodiment,

using identical core material, about 80 ppi may be optimal in the caseof a fully reticulated foam whereas about ppi may be optimal for apartially reticulated or non-reticulated foam. The requirement forincreased pore size with decreasing degree of reticulation may bemodified by perforating the partially or nonreticulated foams.Accordingly, a suitably perforated non-reticulated foam may beadvantageously used which has the same or even smaller pore size than afully reticulated foam. Similarly, a reticulated foam having aninsufficient degree of openness may be adequate if suitably perforated.

Because good conformability is desired for many applications andconformability is usually enhanced if the product is stretched slightlywhen applied, the polyurethane foam should have an extent of elasticitysuch that it can be stretched in any direction at least about 10 percentbeyond its original dimension and return upon release and preferablyabout to percent beyond its original dimension. The ultimate elongationbefore rupture is typically substantially greater, e.g., about to 400percent or two to five times its original dimension.

The thickness of the foam should be no more than is sufficient toprovide the desired interlining, barrier and, in the case ofheat-softened cores, the desired insulative effect. An overly thickprotective covering, in addition to increasing the cost of the product,adds to its bulkiness and detracts from the strength of adhesion orcohesion. For example, a surgical wrap should not be substantially inexcess of one-eighth inch, as excessive thickness would render itsusceptible to easy dislodgment during wear. Thus, each of thetwoprotective outer layers is limited to about 1/16 inch or less, e.g.,about l/32 inch.

While'foams as thin as 3 to 5 mils may advantageously be used,particularly in conjunction with a hard core, a preferred minimumthickness is about 8 mils to prevent weakening the product and also tofacilitate manufacture in that slicing foams to such fine dimensions canbe difficult and may not be feasible on a production basis. it should benoted that the use of thin foams may be facilitated if a reinforcingcoating or impregnant is employed. Suitable strengthening impregnantsinclude acrylic latex binders, thermoplastic polyurethane used inemulsion or solution form such as Estane (thermoplastic polyurethanesfor solution application sold by B. F. Goodrich Chemical Co.) andionomer resin dispersions such as described in U. S. Pat. No. 3,322,734and presently sold by E. l. du Pont de Nemours & Company, Inc., underthe trade name Surlyn D 1230. The suitability of other impregnants canreadily be determined by those skilled in the art. The impregnants maybe added by conventional techniques, including padding, gravure roll andthe like.

For protective use around parts of the body and in non-medical andnon-surgical embodiments, one or both outer layers may each have athickness substantially greater than l/ 16 inch. Also, for certainindustrial uses, even substantially thicker outer layers may beemployed, in which case larger pore sizes may be employed consistentwith meeting tackiness specifications.

Where limited stretch or no stretch is desired and conformability is nota particular problem, a material imparting such desired stretchproperties can be substituted for one of the outer layers. For example,in the closure embodiment-hereinafter described which takes the form ofopposed tabs which are overlapped and pressed together for cohesion, thenon-contacting surfaces may comprise a substantially non-stretchablewoven or non-woven fabric, paper, non-woven plastic film or the like.Also, the foam-cementitious core structure of this invention may be usedsolely as a securing means for attaching articles containing the same toanother surface. In such instance the surface of the article itself,which could be flexible or rigid, porous or nonporous, could take theplace of one of the outer layers.

Where flexible sheet material having limited or cont-rolled'elongationor stretch is desired while concomitantly maintaining two potentiallycementitious sides, this can best be accomplished by incorporatingbetween the outer foam sheets stretch-modifying means. Thestretch-modifying means may be placed between the core and one or bothfoam sheets if the stretchmodifying means is sufficiently open to permitthe core material to pass therethrough and be accessible when the foamis compressed, such stretch-modifying means being, for example, threads,open mesh gauze, and the like. If the stretch-modifying means isincorporated within the core, it is not necessary that the same bepervious; and creped paper, closer weave fabric or other suitable meansmay be employed. The stretchmodifying or controlling means may be formedof elas-.

tomeric material where modified strength or enhanced return propertiesare desired. Thus, for example, the stretch-modifying means may beformed of rubber, polyurethane or other elastomer.

Open-cell polyurethane foams useful in preparing the structure of thepresent invention may be obtained from various commercial sources. Theseinclude, for example, 80 ppi, Scott reticulated foam as sold by the FoamDivision, Scott Paper Company, Chester, Pennsylvania, and 65 ppisubstantially non-reticulated P .4104 Foam as sold by the General FoamDivision, Tenneco Chemicals, lnc., N. Y., N. Y.

While the open-cell polyurethane foams are preferred, certainfunctionally equivalent foams, such as, fOFCXfiIflPIC, vinyl foams,styrene-butadiene foams and some'rubber based foams, may be substituted.Because some of these other foams are usually closed cell, perforationthereof to produce pores would be necessary, as those skilled in the artwill recognize in the light of this disclosure.

lTHE CEMENTITIOUS COREMATERIAL The cementitious core can be anyconventional cementitious material which has the characteristicsrequired in the end product, the particular type per se not being partof the present invention other than being a necessary part of theclaimed construction.

In the medical, surgical and orthopedic field, the core must haveacceptable clinical properties, e.g., inert, essentially non-irriatatingand non-allergy forming, and should preferably lend itself tosterilization. Additionally, for medical-surgical purposes, the core ispreferably porous to complement the porosity of the outer layers,resulting in a product which breathes and minimizes maceration of theunderlying skin. It should be noted in this connection that suchporosity can be accomplished by mechanically perforating the compositeproduct.

The core must have sufficient softness at the temperature of use toextend through the pores of at least one protective covering uponapplication of moderate compressive force so as to be available on theouter surface thereof for adhesion or cohesion. On the other hand, thecore should not be so soft as to flow'or otherwise prematurely becomeavailable at the outer surface of the covering, as for example uponunintentional application of slight pressure or merely upon theapplication of heat.

A useful measure of this requisite softness is the socalled Williamsplasticity as determined, at a specific reference temperature, with aWilliams Plastometer, using a ball of core material weighing 2 gramswhich is preheated for 15 minutes at the temperature of the test andthen placed between two opposed horizontal plates protected withcontrolled-thickness paper. A 5 kilogram weight is applied to theuppermost plate and the separation of the plates is measured after 15minutes, adjustment being made for the thickness of the paper. Thegreater the separation, the greater the plasticity or the hardness ofthe material. For cementitious material to be used for adhesion orcohesion by the application of moderate pressure at about roomtemperature, the reference temperature for determining Williamsplasticities is F. For those core materials which are to be used atelevated temperatures, i.e. above about F., or more usually at about to200 F., the reference temperature is 180 F. I have found that materialsemployed in accordance with the invention should exhibit a Williamsplasticity of from about 0.4 to about 8 mm. of plate separation.Preferably, the plasticities should range from about 0.7 to about 5 mm.

In the medical-surgical field suitable cementitious materials which canbe formulated to meet these various requirements may be suchpressure-sensitive adhesives as, for example, the well-knownelastomericbased surgical adhesive type masses and the acrylateadhesives presently used in surgical adhesive tape constructions. Oneoperable form of the latter is a pure rubbery copolymer of isooctylacrylate and acrylic acid in a 94:6 ratio, as described in U. S. Pat.No. 2,884,126 (Re. 24,906). Other examples of suitable adhesives are setforth in U. S. Pat. Nos. 2,877,l4l, 2,909,278, 3,307,544 and 3,325,459.

One may use as suitable core materials the commercially availablenatural rubber latices designated Uniroyal NC400 M-30 and Uniroyal 1l-35 X creamed 356 as sold by United States Rubber Company. Othersuitable commercially available rubbers, which are cohesive, include,for example, Natsyn 400, 410 and 450. These are essentially syntheticcispolyisoprene rubbers and are sold by The Goodyear Tire andRubber Co.These rubbers should preferably have antioxidants incorporated so astoprevent their deterioration. Some of the self-adhering siliconerubbers that are suggested in U. S. Pat. No. 3,439,676 may also besatisfactory. A number of the aforementioned materials are sterilizable,thus enhancing their use in medical-surgical embodiments.

Typical Williams" plasticity data obtained on such materials are asfollows:

Williams" Plasticity, mrn.

Core Material (plate separation at 100F.)

Elastomeric-hased, surgical l.62.0

adhesive-type mass (pigmented) Elastomeric-based, surgical l.8-2.2

adhesive-type mass (clear) Acrylic A 2.l2.4

Acrylic B 1.8-2.4 Natsyn 400 4.51-4.53 Natsyn 410 2.12-3.56 Natsyn 4501.85-2.12 Uniroyal NC400 M-30 7.95

See teachings of US. Pat. No. 2,884,126

All of these materials produce good cementitious bandages, although someare better than others. For example, a bandage made with Natsyn 400exhibits essentially no tack, in contrast to the undesired tackiness ofa cohesive bandage made with Natsyn 450. A cohesive bandage made withUniroyal NC400 M-30 also exhibits no tack but the pressure required toobtain substantial coherence is considered excessive.

The formulation of the normally tacky material can be adjusted todecrease or eliminate the tackiness. For example, the addition ofsilicone fluids to a tacky material often renders it substantiallynon-tacky without substantially affecting coherence. Such modificationsgreatly expand the type of core that can be used in making non-tackycohesive bandages, Also, because tack would no longer be a problem,foams having large pores, e.g., to 50 pores per inch or even somewhatless, could be used in making satisfactory bandages if otherrequirements are also met.

All of the foregoing are examples of core material which may be used foradhesion or cohesion at essentially room temperature, without priorheating. In accordance with this invention, a second class of corematerial, particularly useful in the orthopedic field, is designed to beused at elevated temperatures, e.g., above about 120 F. and less thanabout 200 F. Such materials include synthetic and natural trans-1,4-polyisoprene, certain polychloroprenes, certain polycaprolactones, andequivalents thereof. Many of these polymers are characterized by beingcrystalline at room temperature, being non-crystalline at elevatedtemperatures and having a relatively rapid rate of crystallization whencooled to room temperature or below. All have the property of beingmoldable and cohesive at elevated temperatures while reverting to arelatively rigid form after cooling to room temperature or below, roomtemperature generally being considered to be in the range of about 60 to80 F. The polymers are generally compounded with filler, pigments andantioxidants to obtain desired characteristics.

Among suitable polymers is synthetic trans-1,4-polyisoprene, which isdescribed, for example, in British Pat. No. 1,155,556. The polyisopreneshould have at least 85 percent of the isoprene units in the trans-1,4configuration. The synthetic crystalline trans-1,4- polyisoprene may beprepared by polymerizing isoprene in a hydrocarbon or halo-hydrocarbondiluent in the presence of stereo-specific Ziegler type catalysts. Thesynthetic crystalline trans-1,4-polyisoprene can also be used in blendswith other polymeric materials, although a major proportion, i.e., about50 percent or more, preferably 60 percent or more, of the blend shouldbe the trans-1,4-polyisoprene. For example, 100 parts by weight oftrans-1,4-polyisoprene can be blended with up to 50 parts by weight ofsynthetic styrene-butadiene copolymer or acrylonitrile-butadienecopolymer without adversely effecting the useful properties of thetrans-1,4-polyisoprene.

Sources of natural trans-1,4-polyisoprene which may be employed arebalata, gutta percha and related gums. Preferably, purified grades areused, that is, those in which resins, which may interfere withcrystallinity or add to tackiness, have been partially or completelyremoved.

Polymers of chloroprene which may be suitable employed include thoseprepared as disclosed in U. S. Pat. Nos. 2,417,034, 2,426,854, and2,567,117 and in Maynard et al., Journal of Polymer Sciences, 18, 227-34(1955) and Walker et al., Proceedings of the Second Rubber TechnologyConference London, 1948, 69-78. Polymerization is normally carried outusing the conventional redox initiation system well known to thoseskilled in the art of polymerization. Although homopolymers ofchloroprene are preferred, the polymer may contain a minor amount ofanother copolymerizable monomer. Such monomers include styrene, l,3-butadiene, isoprene, 2,3-dichloro-l ,3-butadiene, acrylic andmethacrylic acids and ester and nitriles. Commercially available formsof suitable polychloroprene include Neoprene HC (E. I. du Pont deNemours & Company, Inc.), which is about 97 percent trans-l ,4-polychloroprene.

The polycaprolactone polymers which have been found suitable for thepractice of the present invention are the high molecular weightpolycaprolactones. These polycaprolactone resins can be represented bythe structure I O CH CHaCHaCHzCHzl5-O L a l where n can vary from about100 to 1,000, depending on the particular molecular weight grade.Examples of such high molecular weight polycaprolactone polymers thatare presently commercially available are PCL-300 and PCL-700 asavailable from Plastics Division, Union Carbide Corporation, BoundBrook, N. J. The reduced viscosities of PCL-300 and PCL-O (0.2 g./dl. inbenzene at 30 C.) are respectively 0.3 and 0.7 and correspondapproximately to weight average molecular weights of 15,000 and 40,000.Further information is provided in Union Carbides technical databulletin entitled New Polycaprolactone Thermoplastic Polymers PCL-300and PCL-700.

Typical Williams plasticity data obtained on the foregoing thermoplasticcementitious materials are as follows:

Williams Plasticity, mm.

Core Material (plate separation at lF.)

The thickness of the core depends upon the nature of the material, thethickness and nature of the outer layers and the end use of the finishedproduct. For example in the case of cohesive bandages for use in holdingpads or dressings against the skin wherein l/32 inch outer layers of 80ppi Scott reticulated foam are employed, the core thickness may be inthe range of about 0.5 to 10 mils, whereas in the case of orthopedicwrappings, the thickness may vary from 20 to mils. For other uses,however, wherein thicker foam layers may be utilized, substantiallythicker cores would normally be required. In general, the optimumformulations, thicknesses, and the like can best be determined for aparticular use by experimentation, as will beapparent to those skilledin the art'i'n the light of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be moreclearly understood from the following detailed description of specificembodiments, read in conjunction with the accompanying drawings,wherein:

FIG. 1 illustrates, in magnified cross section, a frag mentary portionof an embodiment of the present invention wherein two outer polyurethanefoam layers and a cementitious core are employed;

FIG. 2 is similar to FIG. 1 and illustrates the embodiment wherein anopen mesh web (or other material) is imbedded in the cementitious core;

FIG. 3 is similar to FIG. 1 except that one of the outer foam layers hasbeen replaced by a fabric backing;

FIG. 4 is similar to FIG. 1 and illustrates the embodiment wherein thecementitious core overlaps into the outer foam layers;

FIG. 5 is similar to FIG. 1 except that the cementitious core comprisesa mass-impregnated foam;

FIG. 6 illustrates the use of the embodiment of FIG. 3 in one form ofclosure; and

FIG. 7 is a schematic diagram illustrating one method of producing theembodiment of FIG. I of the present invention.

It should be understood that the structures are represented in thedrawings by graphic symbols and that the drawings are not to scale. As aresult, the representations necessarily depart from the actualappearances of I the various constructions.

DETAILED DESCRIPTION OF THE DRAWINGS, INCLUDING PREFERRED EMBODIMENTReferring to FIG. 1, a preferred embodiment of the present inventioncomprises outer protective coverings l0 and 12 of compressible open-cellpolyurethane foam, each having a thickness of about l/32 inch and a porecount in the range of about to I20 ppi. The coverings are bonded byconventional techniques to core 14 comprising a cementitious materialhaving sufficient softness at the temperature of use to extend throughthe pores of coverings l0 and 12 when the lat-. ter are compressed. In aspecific embodiment, the core may comprise, for example, Natsyn 400synthetic cispolyisoprene cohesive mass having a thickness of about l-6mils and a Williams plasticity of about 4.5 mm.

Because the core is protected by the outer foam coverings, it is notexposed to the touch or extraneous lint, dirt or dust in normal handlingand presents a neat, clean appearance. It is not tacky or sticky and hasgood unwind properties requiring no removable interliner. Even whenusing a tacky mass as the core, the absence of quick grab" permits it tobe readily moved around on a surface to a desired position. Yet thestructure will readily adhere or cohere upon application of moderatepressure and can be separated again and reused as desired. Thenon-fouling outer coverings also act as cushions to the underlyingsurface, e.g., a bandaged wound.

Another advantageous attribute of the embodiment of FIG. v1 is that thestructure is stretchable and highly conformable, as well as being quiteporous. Where limited stretch or no stretch or other characteristic isdesired, materials imparting such desired properties can be added to theconstruction, as illustrated symbolically in FIG. 2, or substituted forone of the outer foam layers, as illustrated in FIG. 3.

Still another advantage is that, when using a material for the corewhich must first be heated, the coverings provide insulation protectingthe user's hands as well as protecting against premature cooling andhardening of the core.

Specifically, in FIG. 2 an open mesh fabric web (or other desiredmaterial) represented by dashed line 16 may be impedded in the core. Thefabric may comprise, for example, cotton gauze having 20 warp and 20weft threads per square inch. The imbedded web 16 may also comprise avariety of other webs or strands, e.g., woven or non-woven cloth, paper(including micro-pleated and creped paper), woven or non-woven plastic,strengthening strands, filaments, rovings, elastic strands, or fibers ofvarious types, including fiber glass, and the like. While the fabric webis illustrated as being imbedded in the middle of the core, it need notbe and can be disposed adjacent an edge of the core. Also, a pluralityof such webs may also be employed, e.g., a web adjacent each edge of thecore. The web must not, of course, unduly interfere with the ability ofthe core to enter the pores of the outer form covering or coverings.

Alternatively, a non-stretch or limited stretch backing 18 may besubstituted for the foam covering 12 as illustrated in FIG. 3. Forexample, the backing 18 may comprise a tightly woven cloth backinghaving 109 warp and 58 weft threads per square inch or may be formed ofpolymer film, paper or other flexible substantially core-impermeablematerial. This embodiment is particularly useful as a surgical tape orclosure. The foam side has substantially no tack and yet will cohere toan opposed similar foam side when the two foam surfaces are pressedtogether. The backing surface, however, exhibits no tack and nocohesiveness because the tightly woven cloth layer 18 or film does notpermit the core to come through.

FIG. 4 illustrates an embodiment wherein the core 20 is impregnated partway through foam layers 22 and 24. This is advantageously employed inthicker laminates, e.g., one-eighth inch or thicker. The core maypenetrate to within 1/32 inch (or even possibly less) of the foamsurface. Because the core is below the surface, the structure isnon-tacky to the touch but, depending upon the nature of the core, maybe adhered to another surface or cohered to a similar structure bypressing the same together.

A related construction is illustrated in FIG. 5 wherein the cementitiouscore 26 comprises a third foam layer impregnated throughout with thedesired cementitious material.

The foam of cementitious core 26 may or may not be substantiallyidentical to the porous open-cell polyurethane foam making up outerlayers 28 and 30.

FIG. 6 illustrates how the embodiment of FIG. 3 may be employed as aclosure having properties similar to the popular Velcro fishhook-type ofclosure. A typical closure may comprise opposed tabs A and B which arerespectively secured to the two halves of a garment or the like which isto be closed, e.g., disposable surgical gown, disposable diaper or otherarticle. Each of the tabs comprises non-stretch fabric backings 32having an adhesive area 34 at one end of each for adhering the tabs tothe respective portions of the garment or other article to be closed.The adhesive 34 may comprise, for example, a conventional hot melt orthermosettting adhesive. The other end of each tab has secured thereto acohesive mass 36 which is covered by open-cell polyurethane foam 38.Tabs A and B form a closure simply by pressing the foam covered surfacestogether whereby the foam is compressed and cohesive masses 36 contactone another and hold the tabs together.

Production of the embodiments of FIGS. 1 and 2 is illustrated in FIG. 7.Outer coverings comprising opencell polyurethane foam layers 40 and 42are unwound from rolls 44 and 46, respectively, and are coated with thinlayers of a solution 4.7 and 48 of a cohesive core material, e.g., a 12to 15 percent solids solution of Natsyn 400 synthetic cispolyisoprenemass in a mixture of xylene and toluene, from supply vessels 49 and 50by means of coater rollers 52 and 54, respectively. Metering rolls orknives (not shown), or equivalent, may be employed to control thethickness of the mass coating. The coated foam from roller 54 joins thecoated foam from roller 52 at the nip of rolls 58 and 60, where thecohesive coatings are lightly pressed together to form a laminatedstructure 62. The laminated structure is then dried (desolventized) inoven 64, operating at, for example, 250F.-275F., and the resultingproduct 66 is then accumulated on product roll 68.

The embodiment of FIG. 2 is produced by imbedding an open mesh fabric 70(or other desired material) from supply roll 72 into the cohesive mass.This can be readily accomplished by introducing fabric 70 into the nipof rolls 58 and 60 where the cohesive solution layers on each of thefoam layers are joined together. As a result, fabric 70 is imbedded andanchored in the cohesive mass during the drying step.

The embodiment of FIG. 3 may be produced essentially as described abovein connection with the embodiment of FIG. 1 except that a non-foam,substantially impervious backing 18 is substituted for foam layer I2.The embodiment of FIG. 4 may be produced by casting a mass of corematerial on silicon-coated paper, and while the mass is still wet,laying the foam on top and then rolling with moderate pressure so as notto drive the mass all the way through the foam. After drying the massand removing the silicone-coated paper, fold the mass coated foam inhalf, mass to mass, to make the bandage. The embodiment of FIG. may beprepared by thoroughly impregnating a foam layer all the way throughwith the mass to produce the core 26 and then rolling outer layers 28and 30 thereon to produce the laminated structure.

In the case of thermoplastic core material, e.g.,

polycaprolactone, the protective foam may be laminated to the surface orsurfaces of the core material while the latter is in the heated state.For example, the core material may be first extruded and, while stillhot, introduced along with the foam into the nip of laminating rolls.The thickness of the protective foam layer or layers above the corematerial may be controlled by adjusting the gap setting between thelaminating rolls to control, in turn, the penetration of the foam intothe core material.

The present invention will be more clearly understood from the followingspecific examples.

EXAMPLE I A l/32 inch thick, stretchable, open cellular sheet ofnon-reticulated polyester polyurethane foam having a pore density ofabout 60 to about ppi was dipped into a 10 percent solids solution of anacrylic mass (similar to that described in U. S. Pat. No. 2,884,126).The wet sheet was drained, dried and cured at 250 F. To thisintermediate layer, two sheets of uncoated, l/32-inch thick,stretchable, open cellular, polyester polyurethane foam were laminated.The cured mass used in this construction exhibited a Williamsplasticity, at 100 F., of 2.1-2.4 mm.

At room temperature, the resulting bandage or tape was found to be veryair permeable and, when wrapped around a human hand, was found to bevery comfortable. The outer layers did not have a tacky or sticky feel,and the bandage was adhered to itself by the application of moderatepressure. The bandage could be removed withh ease and resecured asdesired.

EXAMPLE 2 An acrylic mass similar to that of Example 1 was cast onsilicon-coated paper, dried in a steam cabinet for about 2 minutes, andthen blown in an oven at 250 F. for about 5 to 7 minutes. The resultingporous mass exhibited a Williams plasticity at 100 F. of 1.8 to 2.4 mm.The mass was laminated in one case to a l/32 inch thick, stretchable,non-reticulated polyester polyurethane foam sheet having a pore densityof 60-70 ppi and, in a second case, to an approximately l/28 inch thicksheet of the same foam. After removing the silicone-coated papers,second layers of the open cellular, stretchable, non-reticulated foamhaving corresponding respective thicknesses were laminated to the masssurfaces.

Each of the resulting tapes or bandages was wrapped, at roomtemperature, around a human finger and then pressed together to gaincohesion. The cohesion for the H32 inch foam was slightly better thanthat for the H28 inch foam.

EXAMPLE 3 A 40 percent solids solution of a pigmented elastomericbased,surgical adhesive type mass in xylene was spread using a bar coater setat 15 mils on a 3-mil Daubert silicone-coated paper. Before the massdried, a sheet of 20 X 12 gauze was laid on top and then on top of thiswas placed a sheet of H32 inch thick, ppi, Scott reticulated foam. Afterlaying another sheet of the silicone-coated paper on top, the sample wasrolled, using light to moderate pressure so that only the lower surfaceof the foam was imbedded in the mass. After rolling, the uppersilicone-coated sheet was removed and the remaining composite was driedin a steam cabinet for 15 minutes at 160 F.

Another mass coated foam sheet was prepared as described in thepreceding paragraph but without using the gauze. The resulting twosheets were removed from their respective carriers and then placedmass-to-mass and rolled lightly to prepare a closure. The Williamsplasticity of the mass at F. was about 1.6 to 2.0

When at room temperature and pressed against itself, the closure formeda very good bond and exhibited no stretch. Because too much of a masslayer was present and was imbedded slightly too deeply in the foam, theclosure exhibited slightly too much tack when pressed firmly.

EXAMPLE 4 As in Example 3, a 40 percent solids solution of a pigmentedelastomeric-based, surgical adhesive type mass in xylene was spreadusing a bar coater set at 15 mils on 3-mil Daubert silicone-coatedpaper. Before the mass dried, l/32-inch thick, 80 ppi, Scott reticulatedfoam was placed on the mass surface. After placing another sheet of thesilicone-coated paper on top, the sample was rolled just hard enough topartially imbed the one surface of the foam in the wet mass. The uppersilicone-coated paper was then removed, and the composite was dried in asteam cabinet for 15 minutes at 160 F. The Williams" plasticity at 100F. was about 1.6 to 2.0 mm.

The resulting mass-coated foam was removed from the silicone-coatedpaper and then laminated, mass surface to mass surface, to acommercially available surgical adhesive tape having a 109 X 58 clothbacking (Z adhesive tape as sold by Johnson & Johnson) to form a closuretape.

When at room temperature and pressed foam layer to foam layer, theclosure tape formed a strong bond and worked very well. The closure tapeexhibited no stretch and had no tackiness on its outer surface. The foamsurface also had no tack when pressed lightly and only slight tack whenpressed heavily.

EXAMPLE Five samples of a bandage material were prepared by spreading a30 percent solids solution of a pigmented elastomeric based, surgicaladhesive mass (same as in Examples 3 and 4) in toluene on a 4-milsilicone-coated paper by means of a bar coater, the setting of thelatter being varied from to 21 mils to produce the various samples. Ineach case, while the mass was still very wet, l/32 inch thick, 80 ppi,Scott reticulated foam was placed on top and then rolled lightly.Following this, the composite was dried in a steam cabinet at 160 F. forminutes. After drying, the mass-coated foam was removed from thecarrier, folded over mass-to-mass, and rolled lightly to produce thecohesive bandage. The "Williams" plasticity at 100 F. was about 1.6 to2.0

Inspection of the five samples showed the following:

Bar

Coater Mass Room Temperature Setting Wt., Cohesion Treated PorositySample in mils oz./yd. By Hand (Visual) l 10 0.26 fair very good 2 13044 good when wound very good tightly 3 16 0.63 very good very good 4 191.07 very good very good 5 2| 1.13 very good very good Two layersweighed. As above indicated, two layers of foam and two layers of massmake up the bandage.

Room temperature peel cohesion tests indicated the following, whenl-inch wide samples were placed against l-inch wide samples and rolledsix times at a rapid rate with a 4% pound roller:

Mass Wt., PeelCohesion, Sample oz./yd.' oz./in. Width 1 0.26 0.7 2 0.442.l to 3.1 3 0.63 5.8 to 8.1

EXAMPLE 6 Four additional samples were prepared as described in Example5 except that the elastomeric-based mass differed slightly, primarily bythe omission of pigment, and the solids content of the mass solution wasvaried. The Williams" plasticity of the dried mass at F. was about 1.8to 2.2 mm.

Inspection of the four samples showed the following:

Room Solids in Bar Mass Temp. Mass Coater Wt., Cohesion Solution,Setting oz./yd.' Tested Porosity Sample Wt.% Mils (2 by hand (Visual)layers) 1 20 2.79 excellent fair 2 30 11 excellent fair 3 20 10 0.89very good very good 4 20 9 0.68 good very good EXAMPLE 7 Four additionalcohesive bandage samples were prepared using the same means as inExample 6 but using a different method of preparation. In each case, themass was spread on a silicone-coated paper carrier, and the foam wasapplied while the mass was wet and then removed before the mass had achance to dry. The mass that adhered to the one surface of the foam wasthen dried for 15 minutes in a steam cabinet at F. The Williamsplasticity of the dried mass at 100 C. was about 1.8 to 2.2 mm. Thebandage was prepared by folding over, mass-to-mass, and then rollinglightly.

Inspection of the four samples showed the following:

Five additional samples were prepared in the same manner as described inExample 5 except that a different mass solution was employed, i.e., a 20percent solids solution of Natsyn 410 synthetic cis-polyisoprene in amixture of xylene and toluene. The Williams plasticity of the dried massat 100 F. was about 2.12 mm.

Inspection of the five samples showed the following:

Bar Room Coater Mass Wt., Temp. 7 Setting ozJyd. Cohesion PorositySample mils (2 layers) Tested (Visual) I (by hand) l 10 0.62 fair fairto good 2 14 0.72 good good 3 16 0.898 very good fair 4 18 1.194 verygood fair to poor 5 20 1.31 very good poor EXAMPLE 9 Tests were run toascertain the extent to which hardness of the mass plays a part in thecohesiveness of the bandages described above. In these tests Natsyn 400synthetic cis-polyisoprene mass having a Williams plasticity at 100 F.of 4.53 mm. and Uniroyal NC 400 'M-30 rubber latex mass having aWilliams plasticity at 100 F. of 7.95 mm. were employed.

The bandages were prepared by laying down the mass on silicone-coatedcarrier paper. For the Natsyn 400, a 14.8 percent solids solution inxylene and a 16 mil bar coater setting were used. For the Uniroyal NC400 M-30, which has a low viscosity, a 62 percent solids dispersion andan S46(c) Meier bar were employed. While the masses were still wet, l/32inch, 80 ppi, Scott reticulated foam was applied and rolled lightly.After drying in a steam cabinet for 15 minutes at 160 F the sheets wereremoved from the carrier paper and folded over, mass to mass, and rolledlightly to provide the bandages.

At room temperature, the bandage made with Natsyn 400 had good to verygood cohesion. The bandage made with the Uniroyal NC 400 M-30 had almostno cohesion unless pressed very hard. Both samples exhibited no tack.

EXAMPLE 10 An industrial-type adhesive (reinforced reclaimed rubbermass) was spread from a 20 percent solids solution in xylene onsilicone-coated carrier paper, using a l6-mil bar coater setting. Whilethe mass was still wet, l/32 inch thick, 80 ppi, Scott reticulated foamwas placed on the surface and roller lightly. After drying in a steamcabinet at 160 F. for 15 minutes, the masscoated foam was removed fromthe carrier. The mass exhibited a Williams plasticity of about 2.1 to2.25 mm. at 100 F.

With the mass surface facing up, the foam was stretched longitudinallyby about 30 to 50 percent and held in that position while strands ofreinforcing fiber glass threads (Owens Corning B150 H 12 636), eachhaving a breaking strength of about 4 pounds, were laid on the masssurface in parallel relationship at a spacing of about one-eighth inchto 3/16 inch. The sample was folded over longitudinally and rolledto'make a glassreinforced cohesive tape having about 14 strands of glassthread per inch width. Tension was released and the tape did shrink backby about 10 to 15 percent of the stretched length. When the tape, atroom temperature, was pulled tight around a box and overlapped about 4to 6 inches and pressed against itself, it bonded well and appeared tobe a good strapping tape.

EXAMPLE 1 l A core material is prepared by blending the followingcomponents in the proportion indicated:

The above ingredients are blended in a Banbury mixer for about to 8minutes. The mixture is sheeted out to form a core material which uponheating to a temperature of 160180 F. exhibits a high degree ofcohesiveness and essentially no tackiness. This core material has aWilliams plasticity, at 180 F., of 3.12

Five samples of a splint forming material were prepared by pressing thecore material to a thickness of 115-118 mils between two platensprotected by silicone coated paper and heated to a temperature of 250 F.Five foam sheets of the various configurations indicated in Table l wereeach placed on a pressed core sample and then imbedded into the core bypressing. Each sample, while still warm, was wound into a roll andallowed to cool to room temperature. The rolls were heated to a suitabletemperature of use, 180 F and the unwind properties were observed andare noted in Table 1, below. To test the bond strength of samplesprepared with each of the foam configurations, a sheet of eachconfiguration was sandwiched between two layers of core material heatedto 180 F. and moderate pressure was applied. The samples were cooled toroom temperature and the bond strengths were observed and are noted inTable 3.

TABLE 1 Approximate Pore Thick- Density ness Unwind Bond Sample FoamType (ppi) (mil) Proper- Strength trees 1 Reticulated 80 30 good good 2Reticulated 80 40 good fair to poor 3 Reticulated 8O 40 good good andperformed 4 Reticulated 30 140-142 good good 5 Porous, non- 60 26 goodfair reticulated Perforating Industries, Linden, N..I.; Pattern 8c: 1[16 inch dia. holes, 3/32-inch staggered pattern, 132 holes per squareinch.

As indicated in Table 1, all of the samples using this relatively hard,non-tacky core material exhibited good unwind properties upon heatingthe rolled product to 180 F., a protective coating as thin as 30 milsbeing sufficient. Table 1 further illustrates the importance of thedegree of openness relative to the thickness of the foam and theresulting bond strength. For example, the relatively small pore sized,reticulated foam of sample 1, i.e., approximately 80 ppi, when appliedin a thick? ness of 30 mils, produced a good bond. When, as in sample 2,the thickness was increased to 40 mils, a decrease in the bond strengthwas noted. This decrease could be cured, however, by providing a largerdegree of openness, for example by perforating, as in sample 3.Alternatively, good bond strength could be achieved with a thick foam byincreasing the degree of openness as by employing larger pore sizes suchas the approximately 30 ppi reticulated foam of sample 4 wherein a goodbond was obtained with an extremely thick foam of to 142 mils. Asillustrated in sample 5, nonreticulated but highly porous foam couldproduce a satisfactory bond strength provided a sufficiently largepore-sized foam was used in combination with a thin layer of foam.

EXAMPLE 12 Five samples of an orthopedic cast forming material were eachprepared with a core of PXCL 4926 (substantially a mixture of highmolecular weight polycaprolactone polymers and fillers) obtained fromUnion Carbide Corporation. The core exhibits, at a temperature above 140F. cementitious properties and tackiness and has a Williams plasticity,at F., of 0.89

For each sample, the core was pressed to a thickness of 60 mils betweentwo platens, protected by silicone coated paper and heated to atemperature of 220 F. Each of the sample cores were sandwiched betweentwo layers of various foam configurations and placed between theplatens, again protected by silicone coated paper and heated to atemperature of 220 F. The platens are then brought together to imbed thefoam layers into the core to a slight degree.

Each sample, while still warm, was wound into a roll and allowed to coolto room temperature. To test the efficacy of the samples as cast formingmaterial, the rolls were heated to a suitable temperature of use, 180 Fand the unwind and tack properties were observed, as noted in Table 2below.

To test the bond strengths of samples prepared with each of the foamconfigurations, two sheets of each configuration were sandwiched betweentwo layers of core material heated to 180 F. and pressed by applyingmoderate pressure. The samples were cooled to room temperature and theresulting bond strengths observed arernoted in, Table;

niently handled. When this heated sheet was wrapped around the hand, theconformability was good and after applying moderate pressure to shapeand cohere the wrapped layers and then allowing the material to cool, astrong, rigid cast was formed.

EXAMPLE 14 A composite product was made in the manner of Example 13 withthe exception that a PXCL 4926 polycaprolactonic compound, having aWilliams plasticity of 0.85 to 0.89 mm. at 180 F., was used.Additionally, the foam used was l/32 inch thick, 80 ppi reticulatedfoam. The composite product was thereafter perforated using Perforatingindustries Pattern 8c comprising oneeighth inch diameter holes on 3/16inch centers. The

perforated composite product was rolled and heated TABLE 2 A prox. Foamp pore thick density ness Unwind Tecki- Bond Sample Foam type (p.p.1.)(mil) properties ness strength 1 Reticuiated 80 40 Good No tack.....Good. 2... ..d 80 30 ..do ..do Excellent. 3.-- Reticulated andperforated'. 80 40 Poor Tacky Do. 4.... Reticulated 80 60 Good Notaek..... Fair to good. 5 Porous, non-reticulated 60-70 26 do do Fair.

Perforating Industries Pattern 8e, supra. W m

As indicated by the above table, sample 1 provided an excellent castforming material that has good unwind properties, exhibited no tackinessin the heated condition, and produced a strong bond. By decreasing thefoam layer thickness, as in sample ,2, the bond strength increased. Insample 3, where the thickness was maintained at 40 mils, and aperforated foam was used, an extremely strong bond resulted; however,the heated sample exhibited tackiness and unwind difficulties. Byincreasing the thickness of the foam used in sample 1, from 40 to 60mils, a product having good unwind and tack characteristics resulted,but some bond strength was lost. Sample 5 indicates that a thin, largepored, non-retibulated foam may be used where bond strength is notcritical, and such a product will have good tackiness and unwindproperties.

EXAMPLE 13 A sample was prepared from a PXCL 4926 polycaprolactonecompound having a Williams plasticity of 0.47 mm. at 180 F. The compoundwas extruded at a temperature of about l60-180 F. into a sheet formhaving a thickness of approximately mils. While still hot, a mil thick,80 ppi, reticulated foam was laminated to one surface of the sheet. Thelaminate was cooled to room temperature and cut into two sheets whichwere then heat laminated together, core material to core material, toform a composite product having a core approximately 60 mils inthickness sandwiched between two foam layers. To test the efficacy ofthis product as an orthopedic bandage, the composite product was cutinto strips, heated to approximately l60-165 F., formed into rolls, andallowed to cool to room temperature. The rolls, after being heated at anoven temperature of approximately 170-180 for about 14-20 minutes, couldbe unrolled with ease and exhibited no tacky surface. A splint sheet wasalso cut from the composite product and heated for 10-15 minutes at anoven temperature of 160-l70 F. In this condition, the sheet was nottacky and could be conveand exhibited good unwind properties and notackiness. The heated material was applied as a cast-forming material toa human appendage and moderate pressure was applied. Upon cooling, aconformable, highly porous, strong cast was formed.

EXAMPLE 15 A core is prepared by blending the following components inthe proportions indicated.

Parts by Trans- 1 ,4-polyisoprene Weight (Polymer CorporationXPRO-B-528) 80.0 Finely-divided precipitated hydrated silica (PittsburghH1 811233) 16.0 Titanium dioxide pigment (Titanium Pigment CorporationTitanox ALO) 4.0 lonol Antioxidant (supra) 0.8

The above ingredients are blended in a Banbury mixer for about 5-8minutes. The mixture is sheeted out to form a core which upon heating toa temperature of 180 F. exhibits a high degree of cohesiveness, isnon-tacky and has a Williams plasticity, at 180 F of 2.17 mm.

Six samples of a splint forming material were prepared by pressing thecore material to a thickness of -118 mils between two platens protectedby silicone coated paper and heated to a temperature of 200 F. Six foamsheets of the various configurations indicated in Table 3 were eachplaced on a pressed core sample and then imbedded to a slight degreeinto the core by pressing. Each sample, while still warm, was wound intoa roll and allowed to cool to room temperature. The rolls were heated to180 F. and the unwind properties were observed and are noted in Table 3.

To test the bond strength of samples prepared with each of the foamconfigurations, a sheet of each configuration was sandwiched between twolayers of core material heated to 180 F. and moderate pressure wasapplied. The samples were cooled to room temperature and the bondstrengths were observed and are noted in Table 3.

tion of the present invention may be advantageously emra sd. y r n t tas s n i 31 W y. s

TABLE 3 Pore Foam Number density thickness of Unwind Bond Sample Foamtype (p.p.l.) (mil) layers properties Taclrmess strength 1 Reticulated80 30 Excellent. 2 do 8O 40 Good. 3 -.do 80 60 Poor. 4 Retlculated andperforated- 8O 40 Excellent. 5... Non-retlcu te 60-70 26 Fair. 6Reticulated 30 140-142 Good.

relatively large pores, is useful only where a strong bond is notrequired. Sample 6 shows that a satisfactory product can be made usingextremely large pored, thick foam.

MISCELLANEOUS APPLICATIONS As those skilled in the art will recognize,the construction of the present invention lends itself to a variety ofapplications, both inside and outside the medical, surgical ororthopedic fields, in addition to those already suggested. It can alsobe modified for particular applications, one contemplated modification,already suggested hereinabove, involving the substitution ofsubstantially rigid structure, which may be porous or non-porous, forone of the outer coverings. Thus, the invention may be utilized inmaking floor coverings or the like in which a tile or other floorcovering material replaces, for example, backing 18 of FIG. 3, therebyproviding a tile that can be moved at will until pressed into intimatecontact with the surface to which it is to be adhered. Anotherapplication of this modification is using the back of a plaque or thelike as one of the coverings, whereby the plaque may be readily securedto a wall surface merely by pressing it thereagainst. 7

Also, it is not essential that the products of the present invention bein flat or essentially sheet form. The

limiting.

While the present invention has been described in connection withcertain embodiments, many other alternatives and equivalents areconsidered within the spirit and scope of the invention and coveragethereof is intended by the claims hereafter appended.

1. A medical cementitious wrapping for application to a living body partcomprising an open cellular foam layer, free of cementitious material inits outer depths on the body part facing side and a layer ofcementitious material on the non-body part of the facing side beingnon-tacky at room temperature or less; said cementitious material, atbody tolerable temperatures, being cementitious and sufficiently fluidto impregnate the foam layer, migrate to the body facing side, and beavailable there for cementation by application of moderate pressure.

2. The medical wrapping of claim 1 wherein the cementitious material hasa William plasticity of about 0.4 to about 8.0 mm.

3. The medical wrapping of claim 2 wherein the foam layer is apolyurethane foam.

4. The medical wrapping of claim 2 wherein the foam is reticulated andhas a pore density of about 20 to about pores per inch.

5. The medical wrapping of claim 2 wherein the cementitious materialcomprises a pressure-sensitive adhesive.

6. The medical wrapping of claim 2 wherein the cementitious materialcomprises a thermoplastic polymer.

7. The medical wrapping of claim 6 wherein the cementitious materialcomprises polycaprolactone.

8. The medical wrapping of claim 6 wherein the cementitious materialcomprises trans-1,4-polyisoprene.

9. The medical wrapping of claim 6 wherein the cementitious materialcomprises polychloroprene.

10. The medical wrapping of claim 2 wherein the ce- "22 t UNITEDs'm'rssmrsur oFFIQE 1 V I CERTEFECATE @F RRETIUN Petent No. 3,763,858Dated October 9, 973.

Inventor(s) George ese It is certified that error appears in the eboveidentified patent and that said Letters Patent are hereby eorrecte asshown below:

In Column 2, line 3h, "uppon" should reed upon In Column 5, line 57,"non-irriateting" should read non-irritating In Column 7, line63,'"effecting" should read affecting In Column 8, line 3, "suitable"should read suitably In Claim 1, line 5, after the word "part" andbefore the word "facing", delete the words "of the".

-In Claim 1, line 5, after the word "side" and before the word "being",insert the words --;said wrapping In Claim 1, line 6, after the words"cementitious material" and before the words "at body", insert the wordswhen said wrapping is In Claim 1, line 8, after the word "body" andbefore the word "facing", insert the word pert Signed and sealed this8th day of October 1974.

(sEAL) httest:

MCCOY M. GIBSON JR. Cw MARSHALL DANN Attesting Officer Commissioner ofPatents

2. The medical wrapping of claim 1 wherein the cementitious material hasa William plasticity of about 0.4 to about 8.0 mm.
 3. The medicalwrapping of claim 2 wherein the foam layer is a polyurethane foam. 4.The medical wrapping of claim 2 wherein the foam is reticulated and hasa pore density of about 20 to about 120 pores per inch.
 5. The medicalwrapping of claim 2 wherein the cementitious material comprises apressure-sensitive adhesive.
 6. The medical wrapping of claim 2 whereinthe cementitious material comprises a thermoplastic polymer.
 7. Themedical wrapping of claim 6 wherein the cementitious material comprisespolycaprolactone.
 8. The medical wrapping of claim 6 wherein thecementitious material comprises trans-1,4-polyisoprene.
 9. The medicalwrapping of claim 6 wherein the cementitious material comprisespolychloroprene.
 10. The medical wrapping of claim 2 wherein thecementitious material has a porous structure.